Stability-Indicating Densitometric High-Performance Thin-Layer Chromatographic Method for the Quantitative Analysis of Biomarker Naringin in the Leaves and Stems of Rumex vesicarius L.

JPC – Journal of Planar Chromatography – Modern TLC - A simple, sensitive, and stability-indicating high-performance thinlayer chromatography (HPTLC)-densitometric method was developed...     

Concurrent Analysis of the Biologically Active Markers β-Amyrin and β-Sitosterol by Applying a Validated High-Performance Thin-Layer Chromatography Method in the Aerial Parts of Tinospora cordifolia and Calotropis gigantia

JPC – Journal of Planar Chromatography – Modern TLC - In this study, we have developed a validated high-performance thin-layer chromatography (HPTLC) method for the concurrent...     

Box–Behnken Design (BBD)-Based Optimization of Microwave-Assisted Extraction of Parthenolide from the Stems of Tarconanthus camphoratus and Cytotoxic Analysis

Parthenolide, a strong cytotoxic compound found in different parts of Tarchonanthus camphoratus which motivated the authors to develop an optimized microwave-assisted extraction (MEA) method using Box–Behnken design (BBD) for efficient extraction of parthenolide from the stem of T. camphoratus and its validation by high-performance thin-layer chromatography (HPTLC) and cytotoxic analysis. The optimized parameters for microwave extraction were determined as: 51.5 °C extraction temperature, 50.8 min extraction time, and 211 W microwave power. A quadratic polynomial model was found the most suitable model with R² of 0.9989 and coefficient of variation (CV) of 0.2898%. The high values of adjusted R² (0.9974), predicted R² (0.9945), and signal-to-noise ratio (74.23) indicated a good correlation and adequate signal, respectively. HPTLC analyzed the parthenolide (R_f = 0.16) content in T. camphoratus methanol extract (TCME) at λ_max = 575 nm and found it as 0.9273% ± 0.0487% w/w, which was a higher than expected yield (0.9157% w/w). The TCME exhibited good cytotoxicity against HepG2 and MCF-7 cell lines (IC₅₀ = 30.87 and 35.41 µg/mL, respectively), which further supported our findings of high parthenolide content in TCME. This optimized MAE method can be further applied to efficiently extract parthenolide from marketed herbal supplements containing different Tarconanthus species.     

Heat transfer and friction factor characteristic of spherical and inclined teardrop dimple channel subjected to forced convection

An experimental and numerical investigation is performed in order to determine the outcome of dimple geometries on the heat transfer and friction factor in a dimple cooling channel subjected to turbulent flow. Two geometries taken into consideration are spherical and inclined teardrop. In order to have a better comparison between the two different dimple channel, the dimple depth, total wetted area of dimple, and dimple pitch have been kept constant. In case of spherical and inclined teardrop dimple channels, heat transfer augmentation, friction losses, and flow pattern have been obtained for a Reynolds Number range from 14,000 to 65,000. The investigation shows that the dimple geometry has a significant contribution to increasing the heat transfer augmentation and determining the flow pattern. The inclined teardrop dimple arrangement shows the maximum heat transfer that is 17% higher than the spherical dimple channel, whereas inclined teardrop dimple results in the rise of friction factor of about 5.93–16.14% times as compared to the spherical dimple within the specified Reynolds number. The inclined teardrop and spherical dimple channel show the heat transfer enhancement of 2.74 to 3.20 times and 2.38 to 2.68 times than that of smooth channels provided thermal boundary conditions and flow conditions are kept same. The numerical study has been performed, which provided a detailed insight into the flow structures and vortex formations in spherical and inclined teardrop dimple channel.     

Isolation and validated HPTLC analysis of four cytotoxic compounds,including a new sesquiterpene from aerial parts of Plectranthus cylindraceus

We report isolation of a new sesquiterpene (compound 2: plectranol A) along with three known compounds (1: maaliol, 3: penduletin and 4: chrysosplenol D) from the aerial parts of Plectranthus cylindraceus Hoechst. Ex. Benth ethyl acetate extract (PCEAE). Their structures were established by UV, IR, NMR (¹H & ¹³C), HRESIMS and HSQC methods. The MTT cell proliferation assay of the compounds and the extract performed on human breast, skin and cervical cancer cell lines showed high toxicity, and their IC₅₀ (μg/mL) values were determined. The validated HPTLC analyses of maaliol and PCEAE (method I) and, penduletin, chrysosplenol D and PCEAE (method II) furnished sharp and compact peaks. The estimated high contents (μg/mg) of maaliol (17.06), penduletin (39.36) and chrysosplenol D (31.66) in PCEAE approved the plant’s cytotoxic property. Since, P. cylindraceus contains a variety of cytotoxic terpenoids and flavonoids; our data warrant its further phytochemical and biological characterisation towards developing promising anti-cancer drugs.